The European Commission plans to raise the ceiling of future fines on Microsoft to 3 million Euros (USD 3.8 million) a day if the company continues to defy an antitrust decision, a diplomatic source said on Monday. He was speaking as European competition regulators met to discuss the amount of a fine the European Union's executive arm will impose on the software giant for failing to comply with the 2004 decision that it abused its dominant market position.